An IP address is just one of many available addresses in a subnet.
It depends on the mask, and so depends on the subnet you're in. If you just randomly change your IP address to a subnet, say from first subnet to second subnet, then you don't have special privileges to first subnet as you did when you were in it.

Well in that case, you have two cases (that I can think of on the top of my head

):

If you want all of them old and new stations to be able to share all resources, you can put them in one big local network by changing the mask to 255.255.0.0. What this means is that all of your stations (2^16-2 possible stations for that mask) are in one big network, 192.168.0.0 or whatever you choose it to be.

If you want the new 2 hundred and some new stations to be separate from the old ones, then your way is ok. That is place them in a new network (new broadcast domain). For that the mask gotta be 255.255.255.0. This mask provides only 254 IP addresses: x.x.x.1 up to x.x.x.254. The other two possible addresses are x.x.x.0 and x.x.x.255 are used to refer to the whole network x.x.x.0, and broadcast address (x.x.x.255).